nest of a solitary ground-nesting bees with a
“chimney” extending from nest entrance.
The annual market value of animal pollination has been estimated at £180-442 billion worldwide. Ways to provide floral resources for pollinators are well developed; however, methods for provisioning areas for ground-nesting bees are poorly understood. This is a very important gap in knowledge if we consider that around 64% of approximately 20,000 known bee species are ground nesters. Solitary bees need both flowers for food and a place to live, such as bare ground to nest in. The increasing number of studies highlighting the effectiveness of several ground-nesting bee species as crop pollinators suggest that we should focus on understanding their nesting needs and providing the appropriate nesting resources.
In this study, the nesting preferences of solitary ground-nesting bees were determined by creating eight 20m2 bare ground nesting plots at NIAB East Malling Research, UK. Nine soil parameters were measured along with recording the peak nest density of plots. The soil parameters were hydraulic conductivity (soil’s water absorbance rate), soil compaction (soil hardness), soil moisture, soil temperature, soil stoniness, soil organic matter, soil root biomass, soil texture and vegetation cover. Soil stoniness and soil temperature at 10cm depth were determined as favourable factors, whereas vegetation cover and hydraulic conductivity were determined as the non-favourable factors by ground-nesting bees for nesting.This study provides novel insights into the habitat preferences of ground-nesting bees and shows how the creation of bare-ground plots can be used to enhance the populations of ground-nesting bee species. The findings shared here would underpin more general implications for the sustainable management of a largely overlooked group of bee species, which have a central role in food security.